CN101631886B - Steel ingot for forging and integral crankshaft - Google Patents
Steel ingot for forging and integral crankshaft Download PDFInfo
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- CN101631886B CN101631886B CN2008800056584A CN200880005658A CN101631886B CN 101631886 B CN101631886 B CN 101631886B CN 2008800056584 A CN2008800056584 A CN 2008800056584A CN 200880005658 A CN200880005658 A CN 200880005658A CN 101631886 B CN101631886 B CN 101631886B
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D7/00—Casting ingots, e.g. from ferrous metals
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Forging (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Heat Treatment Of Steel (AREA)
- Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
Abstract
The invention provides a steel ingot for forging and an integral crankshaft having excellent fatigue properties and hydrogen cracking resistance. In the steel ingot for forging, produced with use of a casting mold, the density DBOT of inclusions having 5-10 mum major diameter observed on a steel cross section at the lower part of the steel ingot, is 10-80 pieces/cm<2>; the density DTOP of inclusions having 5-10 mum major diameter observed on the steel cross section at the upper part of the steel ingot is 20-90 pieces/cm<2>; the density of inclusions having >=40 mum major diameter observed on the steel cross section is <=5 pieces/cm<2> on both of the lower part of the steel ingot and the upper part of the steel ingot, and the densities satisfy the relationship (D<TOP>)/(D<BOT>)>=[S(ppm)]/18. The integral crankshaft is manufactured by hot forging the steel ingot for forging.
Description
Technical field
The integral crankshaft that the present invention relates to forging ingot and make by forging ingot.Forging ingot of the present invention and integral crankshaft are extensively applied flexibly effectively at industrial fields such as machinery, boats and ships, generators, particularly are suitable for such as the such parts that require to have high-fatigue strength of turning motion parts.
Background technology
In patent documentation 1 (the open 2006-336092 communique of Japanese Patent), record and narrate following a kind of forging steel is arranged, for the crackle of the anti-hydrogen property raising of the bent axle that makes boats and ships, contained maximum chord length is that the mean value of circularity of the above inclusion of 1 μ m is (hereinafter referred to as average roundness in the steel.) be more than 0.5, maximum chord length is the every 100mm of number of the above inclusion of 20 μ m
2Be lower than 40, this average roundness is more than 0.25 and maximum chord length is the every 100mm of number of the inclusion of 1～10 μ m
2Be more than 100.
In patent documentation 2 (the open 2002-194502 communique of Japanese Patent) record following a kind of steel plate is arranged, for the cutting property of quilt that improves bent axle and the purpose of wear resistant, it constitutes that C:0.62～0.80%, Si:0.60% are following, Mn:0.30～1.80%, S:0.04～0.35%, Cr:0.05～0.50%, Al: be lower than 0.005%, O:0.0020% is following, surplus Fe and unavoidable impurities, being organized as after the forge hot just analysed the perlite main body of ferrite branch rate below 3%, and contains the following sulfide-based inclusion of thickness 20 μ m.
Summary of the invention
In the parts that boats and ships are used, what become problem in recent years especially is, because hydrogen crackle that the defective of hydrogen causes and because the reduction of the fatigue strength that inclusion defects causes.Yet, in the above-mentioned existing technology, even, under harsh environment for use, still do not have the forging ingot that is difficult to sufficient fatigue characteristic of destructive and the sufficient crackle of anti-hydrogen but manufacture by cutting property and wear resistant excellence.The present invention does in view of this situation, and its purpose is, this two side of a kind of fatigue characteristic and the crackle of anti-hydrogen property is provided all excellent forging ingot and integral crankshaft.
In order to prevent the hydrogen crackle, can make the MnS that catches the hydrogen in the steel usually is that inclusion is distributed in the steel.But,, the fatigue characteristic of steel are reduced though the inclusion of MnS system makes the raising of the crackle of anti-hydrogen property.Therefore, improve simultaneously that to be in this balance relation crackle of the anti-hydrogen property and the both sides of fatigue characteristic down very difficult.
Under situation like this, present inventors find, even among a steel ingot, constituting hydrogen concentration in the steel of reason of hydrogen crackle can be than at steel ingot bottom height on steel ingot top.Find out when further studying, the ratio of the inclusion density of steel ingot top, bottom and satisfy when necessarily concerning with the concentration of the S (sulphur) of the formation close relation of inclusion, can not make the fatigue strength reduction of steel ingot just can prevent the hydrogen crackle of forging ingot, thereby finish the present invention.
Can reach the forging ingot of the present invention of above-mentioned purpose, be the forging ingot that forms by mold, wherein, in the end of gravity direction, is steel ingot bottom to 20% of steel ingot height overall with interior position in this end, the density D of the inclusion of viewed major diameter 5～10 μ m in the steel cross section
BOTBe 10～80/cm
2, in the end of the opposition side of described steel ingot bottom, be steel ingot top to 20% of steel ingot height overall with interior position in this end, the density D of the inclusion of viewed major diameter 5～10 μ m in the steel cross section
TOPBe 20～90/cm
2, the density of the inclusion in the steel cross section more than the viewed major diameter 40 μ m in described steel ingot bottom, described steel ingot top is 5/cm
2Below, and satisfy following formula (1).
[formula 1]
(D
TOP)/(D
BOT)≥[S]/18·····(1)
Wherein, the content (quality ppm) of the S in [S] expression steel.
Above-mentioned forging ingot, recommend to contain as follows:
C:0.2～0.6% (the meaning of quality %.Down together.)、
Si：0.05～0.5％
Mn：0.2～1.2％
Ni：0.1～3.5％
Cr：0.9～2.5％
Mo：0.1～0.7％
V：0.005～0.2％
Al：0.01～0.1％
Below the S:0.005%
Below the Ti:0.005%
Below the O:0.0015%,
Surplus is made of iron and unavoidable impurities.
Can reach the integral crankshaft of the present invention of above-mentioned purpose, make by the above-mentioned forging ingot of forge hot.
According to the present invention, the density of the small inclusion by adjusting the steel ingot bottom, density with the thick inclusion on the density of the small inclusion on steel ingot top and steel ingot bottom, steel ingot top, and make the ratio of inclusion density of steel ingot top, bottom and the S concentration in the steel satisfy certain relation, thereby can make the forging ingot of fatigue characteristic and the crackle of anti-hydrogen property excellence.And, by this forging ingot of forge hot, can make the integral crankshaft of fatigue characteristic and the crackle of anti-hydrogen property excellence.
For example, in existing bent axle, suppose the pairing load of output rating of each cylinder 2000kW, but the bent axle that large ship is from now on used etc., in order to comply with to improve fuel efficiency is the miniaturization of purpose, light-weighted hope, needs it to have the fatigue characteristic that can tolerate this.No matter the size of bent axle for this reason, all needing durable qualification is more than 0.45 than (fatigue strength/tensile strength), and has according to this, can improve the bent axle that satisfies this important document.
Description of drawings
Fig. 1 is the figure of expression by the state that solidifies of the steel ingot of ingot casting method manufacturing.
Fig. 2 is the figure of expression by the steel ingot of ingot casting method manufacturing.
Fig. 3 is a SEM photo of observing the steel cross section with 2000 times.
Fig. 4 is a SEM photo of observing the steel cross section with 200 times.
Fig. 5 is a SEM photo of observing the steel cross section with 200 times.
Fig. 6 is the figure of the hydrogen concentration of expression steel ingot top and steel ingot bottom.
Fig. 7 is the evaluation result of expression about the hydrogen crackle and the endurance strength ratio of steel ingot, is the ratio of the small inclusion density of steel ingot top and steel ingot bottom on the longitudinal axis, is S concentration worker in the steel on the transverse axis.
Fig. 8 is whether the endurance strength of expression steel ingot is better and have or not the figure of hydrogen crackle than, (a) relates to steel ingot top, (b) relates to the steel ingot bottom.
Embodiment
By the steel ingot that ingot casting method is made, as shown in Figure 1, on the steel ingot top of finally solidifying portion as the steel ingot bottom and the conduct in precipitation crystal zone, the density of inclusion uprises.Therefore, be the crackle of the anti-hydrogen property of steel ingot and the part of the remarkable anti-Xie of fatigue characteristic in steel ingot bottom and steel ingot top, be suitable as the position of the characteristic of specific steel ingot.
Also have, in the present invention, as shown in Figure 2, be defined as:
The steel ingot bottom: the end of the gravity direction of steel ingot, from this end to the steel ingot height overall 20% with interior position (when having the precipitation crystal zone to generate, the inclusion of precipitation crystal zone part also becomes problem among the described position),
Steel ingot top: the end of the opposition side of steel ingot bottom, from this end to the steel ingot height overall 20% with interior position.
(density (the D of the small inclusion of steel ingot bottom
BOT): be 10～80/cm
2)
As above-mentioned, by making the small inclusion of dispersion in the steel, can make the raising of the crackle of anti-hydrogen property, but in order to bring into play this effect effectively, (major diameter 5～10 μ m) need be 10/cm at the viewed small inclusion in the steel cross section of steel ingot bottom
2More than (20/cm more preferably
2More than, 30/cm more preferably
2More than).On the other hand, even small inclusion, but if too much contain, then shown in the scanning electron microscope photo of Fig. 3～Fig. 5, it forms the inclusion group, can similarly become the starting point of fatigure failure with thick inclusion.Therefore, viewed small inclusion need be 80/cm in the steel cross section
2Below (70/cm more preferably
2Below, 60/cm more preferably
2Below).
Also have in practice, also have the crackle of anti-hydrogen property, consider also that therefore the inclusion that will be lower than 5 μ m also calculates as small inclusion owing to be lower than the inclusion of 5 μ m.But the inclusion that is lower than 5 μ m has the almost same distribution character of inclusion with 5～10 μ m, therefore only calculates the number of the inclusion of 5～10 μ m, still can fully judge the crackle of anti-hydrogen characteristic.Therefore, the inclusion that will be lower than 5 μ m from the object of statistics except, can improve the convenience of mending examination thus.
(density (the D of the small inclusion on steel ingot top
TOP): 20～90/cm
2)
Steel ingot top, the viewed small inclusion in the steel cross section (major diameter 5～10 μ m) need be 20/cm
2More than (30/cm more preferably
2More than, 40/cm more preferably
2More than).In addition as above-mentioned, even small inclusion, but, then form the inclusion group if too much contain, can similarly become the starting point of fatigure failure with thick inclusion.Therefore, viewed small inclusion need be 90/cm in the steel cross section
2Below (80/cm more preferably
2Below, 70/cm more preferably
2Below).
(the density of thick inclusion: 5/cm
2Below)
Because thick inclusion can become the destructive starting point, so steel ingot top and steel ingot bottom both sides, the viewed thick inclusion in steel cross section (more than the major diameter 40 μ m) need be 5/cm
2Below (4/cm more preferably
2Below, 3/cm more preferably
2Below).
((D
TOP)/(D
BOT)≥[S]/18)
When investigating for the hydrogen concentration of steel ingot, present inventors find that as shown in Figure 6, hydrogen concentration compares at steel ingot bottom concentration height on steel ingot top.In addition, also investigate for the crackle of the anti-hydrogen property and the endurance strength ratio on steel ingot top.Its result is presented among Fig. 7.It is (D that Fig. 7 establishes the longitudinal axis
TOP)/(D
BOT), transverse axis is [S], and the crackle of anti-hydrogen property and endurance strength are than be (●) of satisfying specified standards, and ungratified is (*), respectively curve plotting.The criterion of (●/*) of the criterion of (●/*) and " comprehensive evaluation " in table 1 described later～3 is identical.
The concentration (quality ppm) of S in [S] expression steel.As shown in Figure 7, with (D
TOP)/(D
BOT)=[S]/straight line shown in 18 is the border, the situation of (●) occurs at the collinear upside, the situation of (*) occurs at downside.
Show among Fig. 7 that if the high zone of S concentration in steel is (D
TOP)/(D
BOT) value not high, that is, if compare with the steel ingot bottom, the small inclusion concentration on steel ingot top is not high, then on steel ingot top the hydrogen crackle can take place.But it should be noted that the low zone of S concentration in steel, even (D
TOP)/(D
BOT) value not high, the hydrogen crackle can not take place yet.For example at (D
TOP)/(D
BOT) value be lower than under 1 such situation, the hydrogen crackle can not take place yet.
For example, the S concentration in the steel is 0.003% o'clock, and the hydrogen number that is allowed in the steel ingot is 1.5ppm, and with respect to this, if S concentration becomes 0.001%, then the hydrogen number that is allowed becomes low-down 1.0ppm.When making a bent axle by a steel ingot usually, the scope of hydrogen number is about 0.5～1.8ppm.
As described later, present inventors think, also can carry out hydrogen number is suppressed at treatment process below the 1.2ppm, even therefore S concentration is that the hydrogen crackle is taken place, thereby can make forging ingot.Produced the leeway of further reduction S concentration thus.
Usually, reduce S concentration, the hydrogen crackle then takes place easily if will improve fatigue characteristic, but as shown in Figure 7, even reduce S concentration, if satisfy (D
TOP)/(D
BOT) 〉=[S]/18 such conditions, then the crackle of anti-hydrogen property and fatigue characteristic will be maintained.Think thus, also can improve the fatigue characteristic of steel ingot and the crackle of anti-hydrogen property in the past.
(forge hot)
By the forging ingot that above-mentioned ingot casting operation obtains, be formed as the shape of intermediates such as pole afterwards through forge hot.After the shaping, behind intermediate inspection, carry out forge hot once again, be shaped to integral crankshaft and axle journal massive article shapes such as (journal) thus for composition, defective and cleanliness factor etc.Then, implement the thermal treatment of corresponding desired article characteristic after, rebuilding by mechanical workout becomes end article.
The concrete step of making the build bent axle as being used to utilize above-mentioned forging ingot can be listed below operation.That is, solidify the steel ingot that finishes, as the preparation that is used to carry out forge hot, preferably be heated to more than 1150 ℃, more preferably to more than 1180 ℃, further preferably to more than 1200 ℃ from the mold taking-up.By take exercise than forge hot 3 or more be processed into pole shape or stepped thereafter.When this steel ingot forges,, also can after compressing on the steel ingot short transverse, forge again and extend to specified length in order to compress latent defect.The forge hot post-treatment is integral the shape of type bent axle.Also have, when the shaping of integral crankshaft is forged, can single one by one shaping crankshaft crank portion (throw), also can be by mould that integral body is packed into, a plurality of crankshaft crank portion simultaneously is shaped.After moulding is forged, implement the mechanical workout of trimming usefulness and become the integral crankshaft of specified dimension.In addition, be processed into stair-steppingly by forge hot, also can make it become integral crankshaft by mechanical workout.In addition, also can be used as the structure that an end face portion or two ends face at integral crankshaft have flange.The quantity of crankshaft crank portion for example is more than 3, below 12.
(chemical ingredients of steel ingot)
The present invention is as described above, control the size and the density that are present in the inclusion in the steel, the essentially consist of steel is not particularly limited, but for example in order to satisfy as desired intensity of bent axle and toughness, in order to satisfy fatigue characteristic, preferably satisfy following essentially consist in addition according to the general technical level of steel.
(C：0.2～0.6％)
C is the element that helps intensity to improve, and in order to ensure bent axle full intensity is arranged, and for example preferably makes it to contain more than 0.2%, more preferably more than 0.25%, more preferably more than 0.3%.But if the C amount too much, then make the toughness deterioration of bent axle, therefore for example preferably be suppressed at below 0.6%, more preferably below 0.55%, further preferably below 0.5%.
(Si：0.05～0.5％)
Si improves element as intensity and plays a role, in order to ensure bent axle full intensity is arranged, for example preferably make it to contain more than 0.05%, more preferably more than 0.1%, more preferably more than 0.15%, but if too much, the V segregation becomes significantly on the contrary, is difficult to obtain clean steel ingot, and therefore for example making it is below 0.5%, more preferably below 0.45%, more preferably below 0.4%.
(Mn：0.2～1.2％)
Mn improves hardenability, and also be the element that helps intensity to improve, in order to ensure full intensity and hardenability, it is contained more than 0.2%, more preferably more than 0.5%, more preferably more than 0.8%, but the situation of encouraging the V segregation is on the contrary also arranged at most if cross, therefore for example be below 1.2%, to be preferably below 1.1%, more preferably below 1%.
(Ni：0.1～3.5％)
It is useful element that Ni improves element as toughness, for example recommends to make it to contain more than 0.1%, be preferably more than 0.2%, but if the Ni amount is superfluous, then cost rises, and is below 3.5%, to be preferably below 3% therefore.
(Cr：0.9～2.5％)
Cr improves hardenability, and is the effective elements that toughness is improved, and these effects for example make it to contain 0.9% and obtain bringing into play when above, are preferably more than 1.1%, more preferably more than 1.3%.But encouraging the V segregation at most on the contrary if cross, in the situation that is difficult to make high Clean Steel, for example is below 2.5%, to be preferably below 2.3% therefore, more preferably below 2.1%.
(Mo：0.1～0.7％)
Mo is the element that hardenability, intensity, the whole raising of flexible are effectively played a role, and in order to bring into play these effects effectively, for example preferably makes it to contain more than 0.1%, more preferably more than 0.2%, more preferably more than 0.25%.But, because the little microsegregation of equilibrium distribution coefficient (normal segregation) takes place in Mo easily, thus for example be below 0.7%, to be preferably below 0.6%, more preferably below 0.5%.
(V：0.005～0.2％)
V has precipitation strength and organizes micronized effect, is useful element on the high strength of steel.In order to bring into play such effect effectively, recommend to make V for example to contain more than 0.005%, be preferably more than 0.01%.But even contain superfluously, above-mentioned effect also is saturated, causes waste on economy, therefore is preferably below 0.2%, more preferably below 0.15%.
(Al：0.01～0.1％)
Al is effective as the deoxidant element in the steel making working procedure, and is also effective on the anti-crackle to steel in addition.Therefore the Al amount for example recommends to make it to contain more than 0.01%, is preferably more than 0.015%.On the other hand, Al is with form fix N such as AlN, the strengthening effect of the steel that brings except the cooperation that hinders N and V etc., also combine with various elements, generate non-metallic inclusion and intermetallic compound, thereby the situation that also has the toughness that makes steel to reduce, so preference is as being below 0.1%, more preferably below 0.08%.
(S:0.005% is following)
S forms thick inclusion easily in forging steel, therefore have the situation that forging ingot or Crankshaft Fatigue Strength are reduced.Therefore the content of the S in the steel for example is below 0.005%, to be preferably below 0.0045%, more preferably below 0.004%, more preferably below 0.0035%.
On the other hand, the fine S in the forging steel is that inclusion is contained sometimes more than certain density, can form a large amount of stress fields in steel, catches the residual hydrogen that surpasses in the steel of solid solution limit easily, thereby has the effect of the crackle of the anti-hydrogen property of improving steel.
In order to ensure this S is inclusion, and the content that preferably makes the S in the steel is more than 0.0002%, more preferably more than 0.0004%, more preferably more than 0.0006%, more more preferably more than 0.0008%.
S content can be formed by the slag of control during melting and adjusts.Specifically, improve CaO concentration and SiO in the slag exactly
2Ratio (the CaO/SiO of concentration
2: following record is " C/S "), the S content in the steel is reduced.The method of property as a supplement in addition is by improving CaO concentration and Al
2O
3Ratio (the CaO/Al of concentration
2O
3: below, record and narrate be " C/A "), also can reduce the S content in the steel.Otherwise, in the time of strengthening S content, adjust the slag composition and C/S and/or C/A diminished.
(Ti:0.005% is following)
Ti forms thick nitride in steel, the situation that forging ingot or Crankshaft Fatigue Strength are reduced is arranged.Therefore the content of the Ti in the steel for example is below 0.005%, to be preferably below 0.004%, more preferably below 0.003%.Also have, Ti constitutes TiN, TiC, Ti
4C
2S
2Fine inclusion like this and being dispersed in the steel absorbs and catches the residual hydrogen that surpasses in the steel of solid solution limit, thereby has the effect of the crackle of the anti-hydrogen property of improving steel.When guaranteeing that such Ti is inclusion, the content of the Ti in the steel for example is more than 0.0002%, to be preferably more than 0.0004%, more preferably more than 0.0006%.
About Ti content, can recently adjust by the impurity Ti content alloy (low-grade alloy) how in the adjusting auxiliary material and the usage quantity of the poor alloy of impurity Ti (higher-grade alloy).
(O:0.0015% is following)
O (oxygen) forms SiO
2, Al
2O
3, oxide compound such as MgO, CaO and become inclusion, O is the element that the fatigue strength of steel ingot is reduced.Therefore preferably do one's utmost to reduce O, preferred total oxygen demand is below 0.0015%, more preferably below 0.001%.
The preferred basal component of forging steel used in the present invention as mentioned above, the surplus composition comes down to Fe, allows to contain unavoidable impurities in this forged steel.As unavoidable impurities, for example can enumerate P and N, for example P is preferably below 0.03%, more preferably below 0.02%.In addition, also can use the forging steel that in the scope that can not cause disadvantageous effect, also contains other elements energetically to described effect of the present invention.
As the example of other elements that allow actively to add, can enumerate and have the B that hardenability is improved effect, as W, the Nb of solution strengthening element or precipitation strength element, Ta, Cu, Ce, Zr, Te etc., its can add separately or compound interpolation two or more.These add element, for example are preferably below 0.1% to close quantifier.
[embodiment]
Below enumerate embodiment and be described more specifically the present invention, but the present invention is not limited by following embodiment certainly, also can suitably be changed enforcement in the scope that can meet the aim after aforementioned, these all are included in the technical scope of the present invention.
In order to improve the cleanliness factor of the molten steel that injects mold, make the density (D of the inclusion of viewed major diameter 5～10 μ m in steel cross section, steel ingot bottom
BOT) be 10～80/cm
2About, the density (D of steel ingot top inclusion of viewed major diameter 5～10 μ m in the steel cross section
TOP) be 20～90/cm
2About, making the density of the above inclusion of major diameter 40 μ m is 5/cm
2About below, and satisfy formula (1), recommend steel to be carried out refining according to the method for following explanation.
This method of refining is, carry out the secondary refining first time for molten steel from converter or electric furnace steel tapping, processings that outgas of molten steel after finishing for this first time 2 refinings carried out the secondary refining second time for the molten steel after this degassing processing, makes high Clean Steel thus.
That is, to be involved in the inclusion that causes few because of slag in order to make, and has the high Clean Steel of high-cleanness, high, effectively for the molten steel of being made by converter, carries out secondary refining twice by the such order of secondary refining processings → degassing processing → secondary refining processing.
Secondary refining processing for the first time is to make molten composition of steel become the processing of predetermined component, it is the processing of removing of melting the gaseous constituents such as hydrogen that exist in the steel that the degassing is handled, therefore two kinds of processing all need the limit to do one's utmost to suppress to float to being involved in of slag on molten steel surface, and the limit is strengthened and stirred power density.
On the other hand, in the second time, secondary refining was handled, the function of mainly bearing was, make the slag that is involved in the molten steel because the degassing is handled float separation, have and heat the molten steel of maintenance on one side, Yi Bian do not make new slag be involved in generation, the necessity that stirs with low stirring power density like this.
Specifically, in the first time, secondary refining was handled, adjusting the flow of air blast and making the stirring power density was 5W/ton above (being preferably more than the 10W/ton), 60W/ton following (it is following to be preferably 50W/ton), and carry out the slag adjustment, make the slag after the described degassing is handled consist of CaO/SiO
2〉=3.5 and CaO/Al
2O
3=1.5～3.5, and T.Fe+MnO≤1.0 quality %, also having, T.Fe is the meaning of the total amount of iron atom.
During the degassing is handled, adjusting the flow of air blast and make the stirring power density to the mid-term (midway) that this degassing is handled is more than the 50W/ton, be preferably more than the 60W/ton, below the 200W/ton, be preferably below the 180W/ton, thereafter the degassing is handled the flow of (after mid-term) adjustment air blast and made the stirring power density is below the 14W/ton, is preferably 120W/ton following (removing 0W/ton).
In the second time, secondary refining was handled, adjusting the flow of air blast and making the stirring power density was below the 25W/ton, was preferably 20W/ton following (removing 0W/ton).
In more detail according to following steps.
At first, the molten steel from converter or electric furnace steel tapping is transported enforcement secondary refining processing for the first time (also record and narrate later on and be LF-I) to the secondary refining device.Specifically, the limit will be melted steel by making arc-over and taking place and will be heated to T
LAbout=1600 ℃, the limit uses the flux feedway to drop into flux, stirs molten steel from air-blast device spray feed Ar gas again.As the stirring intensity of molten steel, adjusting the flow of Ar gas and making the stirring power density ε that is calculated by following formula (2) is 5～60W/ton.
Also have, in the calculating of stirring power density ε, bottom blown gas be blown into preceding temperature T
o(Ar gas spray into preceding temperature) is normal temperature (298K), after bottom blown gas sprays into, and temperature T
g(Ar gas spray into back temperature) is molten steel temperature T
L
To carry out the initial purified LF-I from the ladle of converter or electric furnace reception steel, mainly melt the heating and the composition adjustment of steel,, then can not make molten composition of steel and the homogenization of molten steel temperature if at this moment suitably do not stir.But superfluous molten steel stirs, although composition and temperature homogeneous are involved in slag easily, the possibility that becomes the defective source after it is big.Therefore, stirring power density ε is 5～60W/ton.Thus, both can prevent that slag was involved in, the composition of molten steel, the homogenization of temperature are achieved.
[formula 2]
ε: stir power density (W/ton)
T
o: bottom blown gas spray into preceding temperature (normal temperature (298k))
T
L: molten steel temperature (K)
M
L: molten steel amount (ton)
ρ
L: molten steel density (kg/m
3)
Q
g: bottom blown gas flow (Nl/min)
T
g: bottom blown gas spray into the back temperature (K)
P: atmosphere pressures (torr)
h
o: the molten steel degree of depth (m)
For example in the secondary refining processing first time (LF-I), though the size of ladle and actual molten steel Intake Quantity M
LEtc. several condition differences, but by making Q
g/ M
LBe 0.30～3.75Nl/minton, then stirring power density ε becomes 4.7～67.2W/ton.
Also have, in LF-I, the kind of flux and amount are to control Heating temperature in the mode that satisfies following three conditions simultaneously, adjust the input amount of auxiliary material (flux): the slag of (in other words being when secondary refining is handled beginning for the second time) consisted of after vacuum outgas processing described later was finished
(i) quality of CaO is with respect to SiO
2Quality be more than 3.5 times,
(ii) the quality of CaO is with respect to Al
2O
3Quality be 1.5～3.5 times,
The summation of the quality of the T.Fe during (iii) slag is formed and the quality of MnO is below 1.0% of slag total mass.
The molten steel that the first time, secondary refining disposed, is implemented vacuum outgas for this molten steel and is handled (also recording and narrating later on is VD) to ladle equal vacuum de-gassing vessel by conveyance.Be exactly to make gas barrier work in detail, the gas by vapor pipe to molten steel top in the ladle discharges, the vacuum state about making atmosphere pressures P in the ladle near 0.5Torr thus.Utilize air-blast device to spray into Ar gas again and stir molten steel.According to above this method, melt the removal of the gaseous constituents such as hydrogen that exist in the steel.
Overall about about 20 minutes of the time of VD,, adjust the flow Q of bottom blown gas at its first half (before the mid-term in treatment time, forebody 10 minutes)
gMake stirring power density ε become 50～200W/ton, latter half (after the mid-term in treatment time, latter half of 10 minutes), the flow Q of adjustment bottom blown gas
gMake stirring power density ε become 140W/ton following (except the 0W/ton).
In VD, the processing that the molten steel that can carry out roughly finishing from the composition adjustment removes dehydrogenation, but at this moment, still preferred employing can make the stirring power density ε that prevents that slag is involved in the molten steel and dehydrogenation is existed side by side.Therefore, at the first half in VD treatment time, stirring power density ε becomes 50～200W/ton, being involved in of slag can either be suppressed at inferior limit thus, can carry out dehydrogenation in high effect ground again.Add at VD latter half ofly,, then will promote to be involved in the separation of floating of slag if will stir power density ε and be suppressed at below the 140W/ton.
In addition, under the situation of present embodiment,, can make high Clean Steel by carry out the secondary refining second time (also record and narrate later on and be LF-II) for the molten steel behind the VD.That is, the molten steel conveyance that vacuum outgas is disposed is in secondary refining treatment unit such as ladle, for molten steel enforcement secondary refining processing for the second time.Specifically, take place by making arc-over, the limit will be melted steel and will be heated to T
LAbout=1600 ℃, molten steel is stirred from air-blast device spray feed Ar gas in the limit.As the stirring intensity of molten steel, adjust the flow Q of Ar gas
gAnd make the stirring power density ε that is calculated by following formula (2) is 25W/ton following (except the 0W/ton).
So, handle (LF-II), can further promote " slag that is involved in separates with floating of deoxidation resultant " of from the VD way, carrying out by carrying out LF once again.At this moment, be involved in order to prevent new slag, needing the stirring power density ε among the LF-II is below the 25W/ton.With heating, the maintenance that this stirring power density ε melts steel, can carry out the separation of floating of deoxidation resultant.
Also have, as described above, because the slag composition of LF-II is:
(i) basicity, CaO/SiO promptly
2〉=3.5,
(ii)CaO/Al
2O
3＝1.5～3.5，
(iii) T.Fe+MnO≤1.0 quality %,
So, with reoxidizing of the molten composition of steel that positively prevents to cause because of the oxide compound in the slag.
The manufacture method of the high Clean Steel by adopting above narration can produce because of slag and is involved in the few high Clean Steel of inclusion that causes.
High clean molten steel with gained is injected into 10～90 tonnes with bottom casting and (makes steel ingot in the mold of height overall 2～4m).After making the steel ingot demoulding of solidifying, be heated to about 1300 degree and implement forge hot, be processed into the forging material of diameter of section 150～700mm.Forge hot is by after with extrusion machine steel ingot itself being extended, and uses special tool to be configured as the circular section and carries out.
In table 1～3, the condition (1～20) that stirring power density ε among demonstration stirring power density ε, the LF-II that stirring power density ε, the VD of the stirring power density ε among the LF-I, VD forebody is latter half of has carried out various changes, also show to be directed to this, with basicity (CaO/SiO
2), CaO/Al
2O
3, T.Fe+MnO (quality %) change and the test (test number 1～59) carried out all conditions and from the top of the steel ingot that obtains, the physical characterization data of the test film that downcuts the bottom.
Also have, in table 1～3, in " composition, temperature homogenization " hurdle, if the change of the C composition in casting initial stage～latter stage of steel ingot is (△ C), when the change of temperature is (△ T), fill in (zero) when △ C≤0.01% and △ T≤20 ℃, other situations are filled in (*).
In " removing of hydrogen " hurdle, before finishing, refining measures hydrogen concentration [H], fill in (zero) during [H]≤1.2ppm, fill in during [H]＞1.2ppm (*).
In " slag is involved in " hurdle, in the microscopic examination of molten steel sample, more than the major diameter 5 μ m, and every 1cm of the inclusion of Ca concentration more than 5%
2The number of field of view is 30 to fill in (zero) when following, surpasses at 30 o'clock and fills in (*).
Show that in table 1～3 S concentration (quality ppm) in the steel of each test film is equivalent to the density (D of the small inclusion (major diameter 5～10 μ m) of the part on steel ingot top
TOP), be equivalent to the density (D of the small inclusion (major diameter 5～10 μ m) of the part of steel ingot bottom
BOT), be equivalent to the density of the thick inclusion (more than the major diameter 40 μ m) of the part on steel ingot top, be equivalent to the density of the thick inclusion (more than the major diameter 40 μ m) of the part of steel ingot bottom.The number of inclusion is according to EPMA (NEC system JXA-8900L), for the every 1cm of micro-minute surface of test film
2The inclusion number investigate.
Also have, chemical ingredients is C:0.3%, Si:0.25%, Mn:0.55%, Ni:1.6%, Cr:1.6%, Mo:0.25%, V:0.01%, Al:0.03%, S:0.002%, Ti:0.003%, O:0.0013%, P:0.01% in the steel of test film.
(D in addition
BOT)/(D
TOPThe value of S concentration (quality ppm) in the) * steel (this value be 18 satisfy formula (1) when following), the size of maximum inclusion (zero expression overall dimension (
Sphere diameter converts)＜0.5mm, △ represents 0.5mm＜overall dimension≤1.0mm, * expression overall dimension＞1.0mm.) measure and the structure that obtains is also shown in table 1～3 about cleanliness factor.Also have, about the project of the difference of the top (T) of not recording and narrating steel ingot, bottom (B), expression relates to the test-results on steel ingot top.
But, in cleanliness factor one hurdle, regulation DIN 3 specifications, DIN K (3)≤15 is zero, DIN K (3)＞15 is * standard, steel ingot top is zero, and the steel ingot bottom is 1 o'clock, cleanliness factor one hurdle is zero, either party be zero and the opposing party for * time, cleanliness factor one hurdle is △, both sides are * time, cleanliness factor one hurdle is *.
In addition, in table 1～3, also record and narrate the test-results of hydrogen crackle of endurance strength ratio, steel ingot top, the bottom of steel ingot top, bottom.
(endurance strength ratio)
According to the result of test for tensile strength described later, Stromeyer test, try to achieve endurance strength ratio=fatigue strength/tensile strength.Endurance strength is represented steel ingot steel ingot top (T), steel ingot bottom (B) respectively in table 1～3.
In addition, endurance strength 〉=0.45 o'clock is (zero), and 0.40≤endurance strength was (△) than＜0.45 o'clock, and endurance strength was (*) than＜0.40 o'clock, judges that endurance strength is than whether excellent results also is recorded in table 1～3 in the lump.
(tensile strength)
Near the steel central part of pole after the forging and pressing, extract
6mm * measurement length 30mm (each 2) tension test sheet is implemented tension test (JIS Z 2204,2241) with normal temperature.Test-results is represented steel ingot top (T), steel ingot bottom (B) respectively with unit [MPa] in table 1～3.
(fatigue strength)
Use test film shown below to be rotated fatigue-bending test.Test-results is represented steel ingot top (T), steel ingot bottom (B) respectively with unit [MPa] in table 1～3.
Test film: the level and smooth test film of diameter 10mm
Test method: revolve winding bent fatigue test (stress ratio=-1, rotating speed: 3600rpm)
Fatigue strength evaluation method: method of finite difference
Differential stresses: 20MPa
Test film number: each 5
The fatigue strength of each test film=(rupture stress)-(differential stresses)
(crackle of anti-hydrogen property)
(forged steel research department compiles, P32-33) for say so in more detail " defectives of forged steel product ", Japan casting forging association to implement ultrasonic test (UT) with the frequency of 4MHz.(1/3～1/5R) when detecting the defective echo of expression hydrogen crackle, the crackle of anti-hydrogen property poor (*), the crackle of anti-hydrogen property excellence (zero) when not detecting from the pars intermedia of steel ingot.But the side (top layer) of establishing the steel ingot width is 0R, when the center is 1/2R, with each position be defined as the centre (1/2～1/3R), pars intermedia (1/3～1/5R), skin section (0R～1/5R).
In " comprehensive evaluation " hurdle, fill in (●) when the test-results of the hydrogen crackle of the endurance strength ratio of steel ingot top, bottom, steel ingot top, bottom all is (zero), other situations are filled in (*).
[table 1]
| Test number | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Condition | 1 | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 5 | 6 | 7 | 7 | 7 | 7 | 7 |
| The ε of LF-I (W/t) | 3 | 5 | 5 | 5 | 5 | 5 | 30 | 30 | 30 | 30 | 60 | 60 | 60 | 65 | 30 | 30 | 30 | 30 | 30 | 30 |
| Composition, equalizing temperature | × | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
| Slag is involved in | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | × | ○ | ○ | ○ | ○ | ○ | ○ |
| Half ε (W/t) before the VD | 150 | 150 | 150 | 150 | 150 | 150 | 150 | 150 | 150 | 150 | 150 | 150 | 150 | 150 | 40 | 50 | 50 | 50 | 50 | 50 |
| Removing of hydrogen | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | × | ○ | ○ | ○ | ○ | ○ |
| Slag is involved in | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
| The ε (W/t) that VD is later half | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Removing of hydrogen | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
| Slag is involved in | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
| The ε of LF-II (W/t) | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 |
| Composition, equalizing temperature | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
| Slag is involved in | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
| CaO/SiO 2 | 4.0 | 3.0 | 3.5 | 3.5 | 3.5 | 7.0 | 3.0 | 3.5 | 3.5 | 8.0 | 3.0 | 3.5 | 8.2 | 3.5 | 3.5 | 3.0 | 3.0 | 3.5 | 3.5 | 8.0 |
| CaO/Al 2O 3 | 2.0 | 1.5 | 1.5 | 1.5 | 3.0 | 2.0 | 1.5 | 2.0 | 2.5 | 2.0 | 2.0 | 1.5 | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 | 1.5 | 1.8 | 2.5 |
| T.Fe+MnO(％) | 1.0 | 0.8 | 1.2 | 0.8 | 0.9 | 0.9 | 0.7 | 0.7 | 1.1 | 0.8 | 0.8 | 0.8 | 0.8 | 0.9 | 0.8 | 0.8 | 1.2 | 1.1 | 0.7 | 0.9 |
| S concentration (ppm) in the steel | 40 | 50 | 30 | 30 | 10 | 45 | 45 | 15 | 40 | 30 | 35 | 15 | 20 | 10 | 15 | 40 | 30 | 20 | 12 | 9 |
| 5-10 μ m inclusion density (T) | 60 | 120 | 90 | 80 | 90 | 88 | 90 | 50 | 92 | 90 | 90 | 80 | 90 | 50 | 40 | 90 | 80 | 90 | 30 | 40 |
| 5-10 μ m inclusion density (B) | 90 | 60 | 60 | 20 | 80 | 25 | 80 | 30 | 60 | 55 | 100 | 80 | 80 | 50 | 62 | 10 | 48 | 70 | 10 | 80 |
| The above inclusion density of 40 μ m (T) | 5 | 10 | 6 | 2 | 1 | 0 | 6 | 5 | 5 | 3 | 7 | 1 | 5 | 7 | 6 | 4 | 6 | 3 | 2 | 1 |
| The above inclusion density of 40 μ m (B) | 6 | 5 | 4 | 5 | 0 | 5 | 6 | 4 | 2 | 4 | 6 | 3 | 5 | 6 | 10 | 2 | 8 | 0 | 1 | 2 |
| B/T×[％S] | 60 | 25 | 20 | 10 | 9 | 13 | 40 | 9 | 26 | 18 | 39 | 15 | 18 | 10 | 23 | 4 | 18 | 16 | 4 | 18 |
| The size of maximum inclusion | ○ | × | × | ○ | ○ | ○ | × | ○ | ○ | ○ | × | ○ | ○ | △ | ○ | ○ | × | ○ | ○ | ○ |
| Cleanliness factor | ○ | △ | △ | ○ | ○ | ○ | ○ | ○ | △ | ○ | △ | ○ | ○ | ○ | ○ | ○ | × | ○ | ○ | ○ |
| Hydrogen crackle (T) | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | × | ○ | ○ | ○ | ○ | ○ |
| Hydrogen crackle (B) | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
| Tensile strength (T) [MPa] | 840 | 900 | 960 | 1021 | 944 | 880 | 870 | 943 | 1023 | 982 | 900 | 1083 | 964 | 812 | 996 | 893 | 1005 | 975 | 925 | 860 |
| Tensile strength (B) [MPa] | 790 | 870 | 900 | 968 | 873 | 820 | 820 | 881 | 943 | 925 | 878 | 1016 | 916 | 737 | 956 | 843 | 986 | 919 | 890 | 827 |
| Fatigue strength (T) [MPa] | 386 | 297 | 346 | 470 | 453 | 431 | 339 | 462 | 348 | 491 | 351 | 520 | 434 | 309 | 329 | 420 | 352 | 468 | 435 | 404 |
| Fatigue strength (B) [MPa] | 300 | 426 | 405 | 455 | 419 | 385 | 320 | 405 | 424 | 426 | 307 | 498 | 440 | 265 | 315 | 422 | 325 | 441 | 427 | 397 |
| Endurance strength is than (T) | 0.46 | 0.33 | 0.36 | 0.46 | 0.48 | 0.49 | 0.39 | 0.49 | 0.34 | 0.50 | 0.39 | 0.48 | 0.45 | 0.38 | 0.33 | 0.47 | 0.35 | 0.48 | 0.47 | 0.47 |
| Endurance strength is than (B) | 0.38 | 0.49 | 0.45 | 0.47 | 0.48 | 0.47 | 0.39 | 0.46 | 0.45 | 0.46 | 0.35 | 0.49 | 0.48 | 0.36 | 0.33 | 0.50 | 0.33 | 0.48 | 0.48 | 0.48 |
| Endurance strength is judged than (T) | ○ | × | × | ○ | ○ | ○ | × | ○ | × | ○ | × | ○ | ○ | × | × | ○ | × | ○ | ○ | ○ |
| Endurance strength is judged than (B) | × | ○ | ○ | ○ | ○ | ○ | × | ○ | ○ | ○ | × | ○ | ○ | × | × | ○ | × | ○ | ○ | ○ |
| Comprehensive evaluation | × | × | × | ● | ● | ● | × | ● | × | ● | × | ● | ● | × | × | ● | × | ● | ● | ● |
[table 2]
[table 3]
Also have, the test number 41,49,55 of table 3, though why the quantity of the thick inclusion of steel ingot bottom is lower than standard, endurance strength be (*) than (B), is because these test film generation hydrogen crackles, owing to the reduction that caused fatigue strength of this crackle.
In addition, Fig. 8 (a) establishes the density (D that the longitudinal axis is the small inclusion (major diameter 5～10 μ m) that is equivalent to the part on steel ingot top
TOP), the density of establishing transverse axis and be the thick inclusion (more than the major diameter 40 μ m) that is equivalent to the part on steel ingot top, comprehensive evaluation be (●) with (●) expression, each is representing with (*) of (*) in the test-results of endurance strength than, hydrogen crackle.(D
TOP) be lower than 20/cm
2The time, the hydrogen crackle takes place, and is (*).
Also has (D
TOP) be higher than 90/cm
2The time, and the density of the inclusion more than the major diameter 40 μ m is higher than 5/cm
2The time, the endurance strength ratio that can not get stipulating is (*).
In addition in Fig. 8 (b), establish the longitudinal axis and be the density (D of the small inclusion (major diameter 5～10 μ m) that is equivalent to the part of steel ingot bottom
BOT), the density of establishing transverse axis and be the thick inclusion (more than the major diameter 40 μ m) that is equivalent to the part of steel ingot bottom, comprehensive evaluation be (●) with (●) expression, each is representing with (*) of (*) in the test-results of endurance strength than, hydrogen crackle.(D
BOT) be lower than 10/cm
2The time, the hydrogen crackle takes place, and is (*).
In addition, (D
BOT) be higher than 80/cm
2The time, and the density of the inclusion more than the major diameter 40 μ m is higher than 5/cm
2The time, the endurance strength ratio that can not get stipulating is (*).
Claims (2)
1. forging ingot, form by mold, it is characterized in that, described steel ingot contains C:0.2～0.6%, Si:0.05～0.5%, Mn in quality %: 0.2～1.2%, Ni:0.1～3.5%, Cr:0.9～2.5%, Mo:0.1～0.7%, V:0.005～0.2%, Al:0.01～0.1%, S:0.005% are following, Ti:0.005% is following, below the O:0.0015%, surplus is iron and unavoidable impurities
And, in the end of gravity direction, be the steel ingot bottom to 20% of steel ingot height overall with interior position in this end, viewed major diameter is the density D of the inclusion of 5～10 μ m in the steel cross section
BOTBe 10～80/cm
2, in the end of the opposition side of described steel ingot bottom, be steel ingot top to 20% of steel ingot height overall with interior position in this end, observed major diameter is the density D of the inclusion of 5～10 μ m in the steel cross section
TOPBe 20～90/cm
2, observed major diameter is that the density of the inclusion more than the 40 μ m is 5/cm in described steel ingot bottom and described steel ingot top in the steel cross section
2Below, and satisfy following formula (1),
[formula 1]
(D
TOP)/(D
BOT)≥[S]/18·····(1)
Wherein, the S content in [S] expression steel in quality ppm.
2. an integral crankshaft is characterized in that, makes by the described forging ingot of forge hot claim 1.
Applications Claiming Priority (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007089336 | 2007-03-29 | ||
| JP089336/2007 | 2007-03-29 | ||
| JP167849/2007 | 2007-06-26 | ||
| JP2007167849A JP5089267B2 (en) | 2007-06-26 | 2007-06-26 | Integrated crankshaft |
| JP207100/2007 | 2007-08-08 | ||
| JP2007207100A JP4160103B1 (en) | 2007-03-29 | 2007-08-08 | Steel ingot for forging |
| PCT/JP2008/054966 WO2008120574A1 (en) | 2007-03-29 | 2008-03-18 | Steel ingot for forging and integral crankshaft |
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| EP (1) | EP2141254B1 (en) |
| KR (1) | KR101121313B1 (en) |
| CN (1) | CN101631886B (en) |
| ES (1) | ES2572612T3 (en) |
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| JP4964211B2 (en) * | 2008-09-30 | 2012-06-27 | 株式会社神戸製鋼所 | Forged product and crankshaft manufactured from the forged product |
| CN101804770B (en) | 2009-02-17 | 2015-03-04 | 株式会社捷太格特 | Wheel bearing device and manufacturing method therefor |
| CN101886227A (en) * | 2010-06-23 | 2010-11-17 | 抚顺泰平铸造有限公司 | ZG28Cr3Ni3Mo steel grade |
| US8562713B2 (en) * | 2011-05-27 | 2013-10-22 | A. Finkl & Sons Co. | Flexible minimum energy utilization electric arc furnace system and processes for making steel products |
| JP5859384B2 (en) * | 2012-06-06 | 2016-02-10 | 株式会社神戸製鋼所 | Large high strength forged steel |
| CN104358855A (en) * | 2014-11-17 | 2015-02-18 | 柳州市二和汽车零部件有限公司 | Oil pump driving gear for automobile |
| CN104533958A (en) * | 2014-11-17 | 2015-04-22 | 柳州市二和汽车零部件有限公司 | Automobile bearing shell |
| CN104455051A (en) * | 2014-11-17 | 2015-03-25 | 柳州市二和汽车零部件有限公司 | Universal joint pin for automobile |
| CN104328327A (en) * | 2014-11-17 | 2015-02-04 | 柳州市二和汽车零部件有限公司 | Crankshaft gear for automobile |
| CN106222564B (en) * | 2016-08-30 | 2018-09-04 | 张家港中环海陆特锻股份有限公司 | Steel ingot and its smelting process avoid steel ingot forging crack method |
| CN106591680B (en) * | 2016-11-09 | 2018-02-23 | 江阴兴澄特种钢铁有限公司 | A kind of technique of continuous casting billet production deep-sea wellhead for production CrNiMo30C steel forging materials |
| CN106987779B (en) * | 2017-05-11 | 2018-08-03 | 北京科技大学 | A kind of metallurgical method of high-strength tenacity crankshaft steel Intragranular Acicular Ferrite |
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| CN1873042A (en) * | 2005-06-03 | 2006-12-06 | 株式会社神户制钢所 | Steel for forging having excellent hydrogen embrittlement resistance and crankshaft |
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| JPH09329147A (en) * | 1996-04-10 | 1997-12-22 | Nippon Seiko Kk | Water resistant long-life rolling bearing |
| JPH108132A (en) | 1996-06-14 | 1998-01-13 | Sumitomo Metal Ind Ltd | Production of thick steel plate excellent in toughness |
| JPH1025536A (en) | 1996-07-11 | 1998-01-27 | Sumitomo Metal Ind Ltd | Steel material excellent in toughness in heat affected zone, and its production |
| JP3491612B2 (en) | 2000-12-28 | 2004-01-26 | 愛知製鋼株式会社 | Crankshaft steel with excellent machinability and wear resistance |
| JP4502929B2 (en) * | 2005-10-20 | 2010-07-14 | 株式会社神戸製鋼所 | Case hardening steel with excellent rolling fatigue characteristics and grain coarsening prevention characteristics |
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- 2008-03-18 KR KR1020097020253A patent/KR101121313B1/en active IP Right Grant
- 2008-03-18 PL PL08722360.8T patent/PL2141254T3/en unknown
- 2008-03-18 WO PCT/JP2008/054966 patent/WO2008120574A1/en active Application Filing
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1873042A (en) * | 2005-06-03 | 2006-12-06 | 株式会社神户制钢所 | Steel for forging having excellent hydrogen embrittlement resistance and crankshaft |
Also Published As
| Publication number | Publication date |
|---|---|
| EP2141254B1 (en) | 2016-05-04 |
| ES2572612T3 (en) | 2016-06-01 |
| EP2141254A4 (en) | 2011-09-14 |
| PL2141254T3 (en) | 2016-10-31 |
| WO2008120574A1 (en) | 2008-10-09 |
| KR101121313B1 (en) | 2012-03-22 |
| CN101631886A (en) | 2010-01-20 |
| KR20090115886A (en) | 2009-11-09 |
| EP2141254A1 (en) | 2010-01-06 |
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